The Nervous System

1.The Central Nervous System consists of the Brain and the Spinal Cord.

2. The Cerebral hemispheres connect senses such as hearing and seeing to the muscles for movement.

3.The cerebellum controls automatic responses such as breathing and the heartbeat.

4.The skull protects the Brain and the Backbone protects the Spinal Cord.

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The Different Parts of The Skin

Sweat Glands: Produce sweat that can be evaporated eventually leaving the body cool.

Nerve Ending: Allow the sking to feel pain, temperature and pressure.

Oil Glands: Produce oil on the skin, leaving the sking soft and waterproof.

Blood Capillaries: Carries blood and regulates temperature.

Effector Muscles: The hairs on the skin rise trapping air next to the skin, leaving the body warm.

Epidermis: The outer layer of the skin

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Responsing To a Stimulus

1. Stimulus: A change in the environment.

2. Receptor: Specialised cells that detect changes in the environment. E.g: the sense organs are receptors, the eye detects light.

3. Effector: Part of the body that produces a response. E.g: muscles contracting to pull the hand away from a hot pan.

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Reflexes

1. Involuntary Response: Are responses that happen without you thinking, they are automatice. As they are automatic they bypass the brain and do not require any thinking.

For example:

Blinking when dust gets in you eye

Ducking down when a ball is thrown at you

2. Voluntary Response: Are responses that need to be decided an dthought through, in this case they do require the brain as a thought process.

For example:

Walking down the street

Talking to your friend

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The Brain

Cerebrum: Thinking, memory and speech.

Temporal Lobe: Language and speech.

Frontal Lobe: Emotion, mood and personality.

Parietal Lobe: Sense organs such as see, touch, taste etc...

Occipital Lobe: Vision.

Cerebellum: Movement.

Pituitary Gland: Secrets hormones.

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Pain

1. Pain is actually created by the Brain after the reflex action has been completed.

2. Reflexes action are very quick and involuntary (which means they happen automatically). They happen very fast which means they are especially useful when in dangerous situations, where the body needs to be protected. The 3 main neurones that are involved in reflexes actions are:

'Sensory neurone ' 'Relay Neurone ' and 'Motor Neurone '

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Synapses

A 'synapse' is the junction or gap between two neurones.

When an impulse is sent from one neurone to another, in the synapses a chemical substance is secreted out of the neurone on it's way to the other neurone. This chemical substance is called 'Neurotransmitters'.

There are 3 main neurones in the brain and they are:

Sensory Neurone: Carries signals from the sense organ (receptor) to the Central Nervous System (CNS).

Relay Neurone: Carries messages to one part of the CNS to the other. E.g: The spinal cord to the brain, vice versa